Re: [PATCHv6 03/37] page-flags: relax page flag policy for few flags

From: Matthew Wilcox <willy@infradead.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	Jan Kara <jack@suse.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Hugh Dickins <hughd@google.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Ross Zwisler <ross.zwisler@linux.intel.com>,
	linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-block@vger.kernel.org
Subject: Re: [PATCHv6 03/37] page-flags: relax page flag policy for few flags
Date: Wed, 8 Feb 2017 20:01:13 -0800	[thread overview]
Message-ID: <20170209040113.GR2267@bombadil.infradead.org> (raw)
In-Reply-To: <20170126115819.58875-4-kirill.shutemov@linux.intel.com>

On Thu, Jan 26, 2017 at 02:57:45PM +0300, Kirill A. Shutemov wrote:
> These flags are in use for filesystems with backing storage: PG_error,
> PG_writeback and PG_readahead.

Oh ;-)  Then I amend my comment on patch 1 to be "patch 3 needs to go
ahead of patch 1" ;-)

> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> ---
>  include/linux/page-flags.h | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
> index 6b5818d6de32..b85b73cfb1b3 100644
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -263,7 +263,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; }
>  
>  __PAGEFLAG(Locked, locked, PF_NO_TAIL)
>  PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD)
> -PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)
> +PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL)
>  PAGEFLAG(Referenced, referenced, PF_HEAD)
>  	TESTCLEARFLAG(Referenced, referenced, PF_HEAD)
>  	__SETPAGEFLAG(Referenced, referenced, PF_HEAD)
> @@ -303,15 +303,15 @@ PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
>   * Only test-and-set exist for PG_writeback.  The unconditional operators are
>   * risky: they bypass page accounting.
>   */
> -TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND)
> -	TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND)
> +TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL)
> +	TESTSCFLAG(Writeback, writeback, PF_NO_TAIL)
>  PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL)
>  
>  /* PG_readahead is only used for reads; PG_reclaim is only for writes */
>  PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL)
>  	TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL)
> -PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND)
> -	TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND)
> +PAGEFLAG(Readahead, reclaim, PF_NO_TAIL)
> +	TESTCLEARFLAG(Readahead, reclaim, PF_NO_TAIL)
>  
>  #ifdef CONFIG_HIGHMEM
>  /*
> -- 
> 2.11.0
> 
> --
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